Need some help from the resident geniuses. I have a 15" MBP with the following hardware installed: Model Name: MacBook Pro Model Identifier: MacBookPro4,1 Processor Name: Intel Core 2 Duo Processor Speed: 2.4 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache: 3 MB Memory: 2 GB Bus Speed: 800 MHz Recently, when I close the notebook and come back to it later, it will have a blank screen. The fans are running so I know it is working, but I've tried everything. All that seems to work is holding the power button until it shuts down and then restarting it. Any advice would be much appreciated. I've searched through the forum and found a few threads that seem to be similar to mine but nothing helped.